Expansible piston



May 27, I930. c. BURNS I 1,760,531

EXPANSIBLE PISTON Filed May 31, 1927' INVENTOR. 3 Leonaraifi'i 15 /726,

, ATTORNEY.

i An adjustable,

Patented May 27, 1930.)

UNITED STATES PATENT oFrIcE LEONARD c. BURNS, or PORTLAND, onneonnxrmsmrn rrs'ron Application filed May 81, 1927. Serial No. 195,504.

plunger, hereinafter termed a piston, of the class referred toconstructed in a manner whereby it can be expeditiously expanded to meetrequirements when the wall of a cylinder has become worn, under suchconditions 1 overcoming the necessity of the employment of an oversizedpiston and the re-boring of the cylinder wal Further objects of theinvention are to provide, in a manner as hereinafter set forth, anadjustable expansible piston which is simple in its construction andarrangement, strong, durable, compact, thoroughly efficient in its use,conveniently adjusted and expanded when desired, readily assembled andcomparatively'inexpensive to set up.

With the foregoing and other objects in View the invention "consists ofthe novel con-v struction, combination and arrangement of parts, ashereinafter more specifically described and illustrated in theaccompanying drawings, wherein is shown an embodiment of the'invention,but it is to be understood that changes, variations and modificationscan be resorted to which fall within the scope 30 of the claims hereuntoappended. In the drawings wherein like reference characters denote.corresponding parts 7 throughout the several views:

Figurel is a vertical sectional view of a piston, in accordancewith'this invention, in a normal position prior to the expansionthereof. I

Figure 2 is a vertical sectional view of the piston adjusted to providefor the expansion thereof.

Figure 3 is a plan view of the retainer plate. Figure 4 is a plan Viewof one of the shims. Figure 5 is an inverted plan view of one of theexpanders. 9

Fi re 6 is a cross sectional view of a modifiedorm of expander. i I

expandible piston, in accordanc with this invention, comprises a corereerred to generally by the reference character 1 and formed of acylindrical portion2 and a tapered portion 3, which at its largerendmerges into the cylindrical portion 4 2 and is inset with respect to theouter edge j of said portion 2 thereby providing in con-.

.nection with the latter a shoulder or seat 4 which extends entirelyaround the pointof mergence of the tapered portion 3 with thecylindrical portion 2. The rear end of the core 1 is formed with aconcave recess 5 69 provide a clearance for the operation of the 50piston rod 6. The recess 5 is of a depth less than half the length ofthecore 1 and extends through the portion 2 and for a short distance inthe portion 3. i

The tapered ,portion 3, of the core 1 is formed with a transverselyextending opening 7 which is intersected centrally thereof by alengthwise extending rectangular slot 8, the latter mergesat its forwardend into an opening 9 which communicates with a socket 70 10 at theforward end of the tapered portion 3. The slot 8, opening 9 and socket10 are arranged at the axis of the core 1. The slot 8 is ofgreaterlength than the opening 9, of.a length greater than the depth of thesocket l0 and opens at its rear end into the recess 5. The diameter ofthe opening 9 is less than the width of slot 8 and socket 10. r

The head of the rod 6, indicated at 11, is positioned within the slot 8and is formed with atransversely extending -o ening 12, throughwhich-extends a wrist vpm 13, the latter being mounted in the opening, 7formed in the tapered ortion 3 of the core 1. The forward end 0 the head11, of the rod 6,'-is spaced from the base of the slot 8 therebyproviding a clearance for the head 11 during the pivoting movementsthereof. r,

Arranged within the forward end of the tapered portion 3, of the core 1,as well as projecting forwardly from the latter is a peripherallythreaded coupling member 14, having its rear end providedwith a head 15a which abuts against the wall at the forward end of the slot 8. Themember 14 extends through, the opening 9 and socket 10 and projects asubstantlal distance forwardly with res ect to the forward end of thebore 1. The unction of the coupling member 14 will be, presentlyreferred to. t

The tapered portion 3, of the core 1 may be of any desired length anddiameter and it is adapted to have mounted thereon a set of expanderelements. These elements can be constructed of any suitable material andthe number of elements of the set can be as desired, depending upon thelength of the tapered (portion 3. By way of exam le' three expan erelements are illustrate as ar-. ran ed in enveloping position withrespect to t e tapered portion 3 of the core 1. The expander elementsare indicated at 16, 17 and 18. The outer'diameter of each of theexpander elements is the same. Each expander element is in the form ofan annulus. The inner faces of each expander element conform in contourto the peripheral shape of the tapered portion 3 of the core 1.Undersuch conditions the inner face of each expander element is taperedand by this. arranger'nent each expander element has the body thereofgradually increasing in thickness in cross section from the followerface to the forward face of the element The body portion of the. element18 is of less thickness than the body portion of the element 17 and thebody portion of the latter is of less thickness than the body portion ofthe element 16.

The outer sides of the expander elements are flush with each other andthe inner side of the expander element 16 forms a continuation of theinner side of the expander element 17 and the inner side of the expanderelement 17 forms a continuation of the inner side of the expenderelement 18. As shown each of the expander elements is provided with asplit and such split is indicated at 19 in Figure 5. It will beunderstood that the body portion of each expander element can be set upother than that as shown to provide for the expansive characteristic ofeach element.

Associated with the expander elements is a set of shims and the shims ofthe set are indicated at 20. Each of the shims is in the forwardly withrespect to the plate 21. Co-

acting with the plate 21 for thepurpose of clamping it in position,whereby the plate in connection with the shims 20 will maintain theexpanders in enveloping position with re-- sp'ect to the taperedportions 3 of the core 1, is clamping nut or sleeve 23 which hasthreaded engagement with the threads of the coupling member 14 and isformed at its forwardend with a laterally extending, annular flange 24which overlaps the plate 21 whereby the latter is clamped in position.

It will be assumed that the normal position of the iston is as shown inFigure 1 and that it is desired to expand the same. When the piston isin normal position, the expander 16 has its forward faceflush with thetapered portion 3 of the core 1. As illustrated by way of example fourshims 20 are employed for the purpose of positioning the expanderelements, so that the element 16 will have its forward face flush withthe for,- ward end of the tapered portion 3. Now it will be assumed thatthe piston is to beexpanded. Two of the shims 20 are removed from theposition as shown in Figure 1 and element is illustrated, and which isindicated at 25. The outer periphery of the element 25 is formed withwagroove 26 to receive a packing element or ring. Otherwise than that asstated the construction of tlfe expander element 25 shown in Figure 6 isthe same as that shown in Figures 1, 2 and 5. p

The piston construction provides means whereby it can be expeditiouslyadjusted and expanded, when occasion requires and especially when thewall of'a cylinder has become I I worn, under such conditions overcomingthe necessity of the employment of an oversized piston and the re-boringofthe cylinder wall. Furthermore the piston construction can be quicklyand expeditiously assembled so that it can be employed with any desiredsize of c linder, new or otherwise. Therefore it is thought the manyadvantages of an expansible piston, in accordance with this inventioncan be readily understood, and althoughvthe preferred embodiment of theinvention is as illustrated and described, yet it is to be understoodthat changes in the details of construction can be had which will fallwithin the scope of the invention as claimed.

What I claim is z 1, In an expansible piston a core formed of acylindrical portion, and a forwardly directed tapered portion of greaterlength and of less diameter throughout than said rear portion, said corehaving its rear end pro vided with a recess extending through said rearportion and into said tapering portion, sald tapering portion formed atits axis with a rectangular, lengthwise extending slot, an v opening anda socket, said opening interposed between and communicating with saidsocket and slot, sald opening being of a diameter less than that of thesocket and less than the width of the slot, said tapering portionfurther formed with a diametrically extendin opening intersectedcentrally thereof by sa1 slot, and said slot opening into said recessand said socket opening at the forward end of said tapered portlon.

2. In an extensible piston a core provided with means for receiving exander elements and further provided at its ongitudinalmedian respectivelwith a rectangular slot to receive the hea of the piston rod, an openingof less diameter than and communicating with the forward end of theslot, a socket communicating at its rearwith said opening and adiametrlcally disposed opening intersecting said slot and ada ted toreceive a wrist pin for the piston rod ead, combined with means forretaining the ex ander elements on the core and including a tu ularelement having a head positioned in the slot forwardly "of the head ofthe piston rod, said element extending forwardly through said openingand 7 socket.

In an expansible piston a core provided intermediate its ends and at itslongitudinal median with a rectangular slot completely open at its rearand partly open at its forward end and providing for the reception ofthe head of a piston rod and for the head at the rear end of a forwardlydirected anchoring means for retaining means for expander elements, andsaid core further'formed with a diametrically disposed wrist pinreceiving opening intersected transversely thereof by said slot;

4. In an expansible piston a core provided with means for receivingexpander elements,

said core formed at its forward end with a socket, at its rear end witha recess and in proximity and in advance of a diametrically disposedwrist pin receiving opening, said core further formed at itslongltudinal median with a rectangular slot for receiving the head of apiston rod, said'slot intersection said opening, open at its rear endand communicating at 1ts forward end with said socket, combined with aforwardly directed, headed anchoring element for a retaining means for vthe expander elements, said anchoring element extending through andprojecting from said socket and having its head positioned in said slotand coacting with the forward end wall of the slot to retain it in thecore, the head of the anchoring element positioned forwardly of the headof the piston rod.

In testimony whereof, Igalfix my signature hereto. p

LEONARD C. BURNS.

